On the surface, winter can look like silence in the Forest Preserves of Cook County. Bare trees, brittle grass and frozen soil make it seem that nature has pressed pause. But look closer and you will find that plants are quietly sustaining themselves and the ecosystems around them even when they appear asleep.

Take skunk cabbage, for example. In a feat that feels almost magical, this wetland plant produces enough heat to melt snow around it. In that clear patch of ground, the skunk cabbage can be the first plant in the area to bloom, luring in early pollinators like flies with its rotten meat smell when little else is available. It’s one of the first hints that spring is stirring beneath the frost.

While skunk cabbage is waking up, many shrubs are still carrying last season’s gifts. Chokeberry, viburnum and other berry-bearing shrubs hold onto their fruit through the coldest months. To a hungry bird searching for nourishment when insects are scarce, those bright berries can mean survival.

Other plants contribute in less obvious ways. The white oak and American hop-hornbeam cling to their dried leaves all winter. This not only discourages browsing animals but also prepares the soil for spring. When those leaves finally fall, they enrich the earth with nutrients right as growing season begins, ensuring the forest floor is ready for the next wave of growth.

Then there are the hollow stems of plants like milkweed and ironweed. What looks like lifeless stalks sticking out of the snow are actually nurseries. About 30 percent of bee species tuck their eggs inside the stems in the fall, where they wait, safe and sheltered, until spring warmth coaxes them out. Small mammals also take cover in these thickets, making even “dead” stems into vital shelters.

Seed heads, too, stay put through the season. The stiff silhouettes of plants like prairie coneflowers are more than winter’s decoration. They’re buffet tables for finches, sparrows and small mammals who depend on the seeds for food when the landscape seems empty.

Along waterways, buttonbush takes on a different role. Its roots form protective tangles at the border of land and water. Turtles, who like to bury themselves in mud, find a home in these root webs, shielded from predators like skunks and racoons that patrol for easy meals.

And beneath the soil, spring ephemerals like trillium wait with patience. They’re poised to rise as soon as sunlight touches the warming earth, blooming before trees leaf out and shade the forest floor.

Dormant does not mean idle. In the hush of winter, plants are feeding, protecting, sheltering and preparing. Without their hidden work, many creatures would not survive the season, and spring would not have the foundation it needs to bloom.